Contract Liabilities: Activity (Details) - USD ($)	3 Months Ended
	Mar. 26, 2022	Mar. 27, 2021
Activity of the current and noncurrent deferred franchise revenue
Balance at beginning of period	$ 8,508,500	$ 8,708,300
Franchise and software license fees collected from franchisees, excluding amount earned as revenue during the period	458,000	355,700
Fees earned that were included in the balance at the beginning of the period	(501,100)	(440,600)
Balance at end of period	$ 8,465,400	$ 8,623,400